Mask used for layer formation and process of making the mask

Description

1. Field of the Invention

[0001] The present invention relates to a mask used when forming a thin layer on a substrate, and a process of fabricating the mask.

2. Description of the Related Art

[0002] Vapor deposition, sputtering, CVD and similar processes are used to form thin layers from various kinds of material. The thin layers are shaped to a certain pattern or configuration, depending upon a purpose of use. If the vapor deposition process is performed with a mask having a fine opening pattern, the vapor deposition process can make a thin layer having a desired pattern.

[0003] In this vapor deposition process, the mask is firmly attached to a substrate prior to vapor deposition. The material is then vapor-deposited on the substrate. The opening of the mask decides (controls) the area of vapor deposition so that a desired pattern of thin layer is made on the substrate. The mask is prepared by, for example, electroforming.

[0004] The process of making the mask by electroforming will be described. First, a plating substrate with photoresist thereon is prepared, and a fine pattern of resist is made on the substrate by photolithography (i.e., the pattern making process). As a result, some areas are covered with the resist and other areas are not on the substrate. Then, a metal is electro-deposited over the no resist areas on the plating substrate (i.e., the electroforming process). After the electroforming, the deposited metallic layer is removed from the substrate (i.e., the peeling or exfoliating process). The peeled metallic layer becomes the mask which has the opening of the same shape as the resist pattern.

[0005] In this manner, the mask has the opening that has a uniform width is prepared. This technique is disclosed in Japanese Patent Kokai No. 10-305670.

[0006] The mask is thin so that the mask is easy to bend. Particularly, the mask bends as the mask becomes larger. If the mask bends during the layer forming process, the opening of the mask changes its shape so that the resulting layer does not have a desired pattern.

[0007] Further, there is known from US-A-3,241,519 a tensioned and cooled mask which forms the basis for the preamble of attached claim 1. Especially, this known mask comprises a frame providing a window and linear masking strips attached to opposing edges of the frame.

[0008] Furthermore, EP-A-0 580 112 describes a manufacturing method of glass optical elements using a mask, wherein this mask also has a frame providing a window and linear shielding elements.

SUMMARY OF THE INVENTION

[0009] According to one aspect of the present invention, there is provided an improved mask assembly having a predetermined opening pattern used to form a thin layer having the same pattern on a substrate. The mask assembly includes a frame having a window. The mask assembly also includes a masking part supported by an edge (periphery) of the window. The masking part includes a plurality of shielding portions spaced from each other to form the predetermined opening pattern. Each shielding portion has a plurality of parallel linear elements arranged next to each other.

[0010] According to another aspect of the present invention, there is provided a method of making a mask assembly. The mask assembly has a predetermined opening pattern used to form a thin layer of the same pattern on a substrate. The method includes providing a masking part that includes a plurality of linear elements arranged next to each other. The method also includes removing predetermined one or more linear elements to form the predetermined opening pattern. Since which linear element(s) should be removed can be determined arbitrarily, it is possible to make the opening having a desired pattern.

[0011] Other objects, aspects and advantages of the present invention will become apparent to those skilled in the art to which the present invention pertains from the subsequent detailed description of the invention and the appended claims, taken in conjunction with the accompanying drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

[0012] 

Figure 1 illustrates a plan view of a mask assembly used for layer formation according to one embodiment of the present invention;

Figure 2 illustrates a cross sectional view of a modified mask assembly according to the present invention;

Figure 3 illustrates a cross sectional view of another modified mask assembly;

Figure 4 illustrates a cross sectional view of still another modified mask assembly;

Figures 5A to 5C are a set of plan views to illustrate a method of fabricating the mask assembly shown in Figure 1;

Figures 6A and 6B are a set of cross sectional views to illustrate a method of fabricating the mask assembly shown in Figure 3; and

Figures 7A to 7D are a set of cross sectional views to illustrate a method of fabricating the mask assembly shown in Figure 4.

DETAILED DESCRIPTION OF THE INVENTION

[0013] A mask assembly according to various embodiments of the present invention will be described with reference to the accompanying drawings.

[0014] Referring to Figure 1, a mask assembly 1 used for layer formation includes a rectangular frame 3 having a rectangular window 2. The frame 3 is a rigid plate member made from, for instance, SUS430 (stainless steel). The frame 3 supports a masking portion 4 on the edge of the window 2. The masking portion 4 is firmly attached to the frame 3 by means of adhesive or other connecting element (not shown). The masking portion 4 generally spans the window 2.

[0015] The masking portion 4 includes a plurality of shielding (masking) parts 6. Each shielding part 6 includes a plurality of parallel linear elements 5 arranged next to each other. The linear element 5 is a resin wire having a 10-micrometer diameter. It should be noted that three linear elements 5 form a single shielding part 6 in Figure 1, but this is for the sake of easy illustration. In actuality, the shielding part 6 includes more linear elements 5. Ends of the linear elements 5 are located on the edge of the window 2 of the frame 3.

[0016] The shielding parts 6 are spaced from each other. The shielding parts 6 and the window 2 in combination define a plurality of rectangular openings 7.

[0017] The mask assembly 1 is used for vapor deposition (layer formation). In a vapor deposition machine, the mask assembly 1 is placed such that the frame 3 faces a substrate across the masking portion 4. A vapor deposition material is supplied from the frame side and passes through the openings 7 to reach the substrate. The material then becomes a thin layer having a certain pattern, which is determined by the openings 7, on the substrate. Such vapor deposition process can make, for example, a bus line for organic electroluminescent elements and/or other parts.

[0018] It should be noted that the linear elements 5 may be stacked in the thickness direction of the frame 3 or mask assembly 1 (i.e., the direction perpendicular to the drawing sheet of Figure 1) so that the masking part has a multi-layer structure. An example of a masking assembly having a multi-layer masking part is illustrated in Figure 2. In Figure 2, the linear elements 5 (5U, 5L) of each shielding part 6A have a two-layer structure. The lower layer is indicated as the "first layer" and the upper layer is indicated as the "second layer." The linear elements 5L of the lower layer are directly placed on the frame 3, and the linear elements 5U of the upper layer are put on the lower linear elements 5L. In Figure 2, each lower linear element 5L is located below the connecting line of two adjacent upper linear elements 5U. Since each lower linear element 5L seals a gap between the associated two upper linear elements 5U, the vapor deposition material supplied, as indicated by the unshaded arrow, does not pass the gaps between the upper linear elements 5U. The vapor deposition material flows through the openings 7 only. The multi-layer masking portion 4A includes a plurality of multi-layer shielding parts 6A to define the modified masking assembly 1A.

[0019] Referring to Figure 3, another masking assembly 1B is illustrated. The masking assembly 1B includes a plurality of modified shielding parts 6B. Each shielding part 6B includes a coating layer 8 that covers the linear elements 5. The coating layer 8 seals a gap between each two adjacent linear elements 5. Thus, the vapor deposition material (unshaded arrow) do not pass the gaps of the linear elements 5. The resulting masking portion is designated at 4B.

[0020] Instead of the coating layer 8, a suitable film may be employed. As shown in Figure 4, a film 9 may be attached over the linear elements 5 of each shielding part 6C. The resulting masking portion is designated at 4C, and the resulting masking assembly is designated at 1C.

[0021] Now, a process of making the mask assembly will be described.

[0022] Firstly, referring to Figure 5A, the frame 3 having the window 2 is prepared. Then, the linear elements 5 are provided on the frame 3 to completely close the window 2 as indicated at 4' in Figure 5B.

[0023] The parallel linear elements 5 are arranged close to each other and firmly attached to the frame 3 by an adhesive or other suitable connector. Arranging and attaching the linear elements 5 may be performed simultaneously or successively. Alternatively, arranging a certain number of linear elements 5, followed by the attaching process, may be repeated until the linear elements 5 close the entire window 2 of the frame 3.

[0024] Tension is applied to the linear elements 5 when the linear elements 5 are attached to the frame 3. Therefore, the linear elements 5 (or the mask portion 4') which span the window 2 do not bend or become loose.

[0025] After the mask portion 4' is fixed to the frame 3, at least one linear element 5 is removed to form the opening(s) 7 as shown in Figure 5C. The width of each opening 7 is determined by the number of the removed linear elements 5 and the diameter of each linear element. Accordingly, it is possible to arbitrarily determine the size (width) of each opening 7. It is also possible to arbitrarily determine the location of each opening 7.

[0026] If the linear elements 5 are stacked, the processes of Figures 5B and 5C are repeated. For example, when the mask shown in Figure 2 is fabricated, the lower layer of linear elements 5L are laid on the frame 3, some of the lower linear elements 5L are removed, and then the upper layer of linear elements 5U are laid over the lower linear elements 5L, and some of the upper linear elements 5U are removed to form the openings 7.

[0027] It should be noted that, as shown in Figure 3, coating layers 8 may be provided over the linear elements 5 to seal gaps of adjacent linear elements 5, before or after the process of Figure 5C. The coating layers 8 may be formed by vapor-depositing a resin on the linear elements 5. This will be described with reference to Figures 6A and 6B.

[0028] When the predetermined linear elements are removed and the openings 7 are formed as shown in Figure 6A, the coating layers 8 are formed over the remaining linear elements 5 as shown in Figure 6B. This is an example when the coating layers 8 are formed after the process of Figure 5C.

[0029] Alternatively, if the coating layer formation is performed before the process of Figure 5C (i.e., if the coating layers 8 are formed over all the linear elements 5), the coating layers 8 applied onto the unnecessary linear elements 5 are removed together with the unnecessary linear elements 5 when the unnecessary linear elements 5 are removed.

[0030] It should also be noted that, as shown in Figure 4, films 9 may be provided over the linear elements 5 to seal gaps of adjacent linear elements 5. The films 9 may be attached to the linear elements 5 by an adhesive. This will be described with reference to Figures 7A to 7D.

[0031] First, the linear elements 5 are arranged side by side as shown in Figure 7A. Then, the film 9 is applied to the linear elements 5 as shown in Figure 7B. The film 9 is, for example, a metallic foil, and is attached to the linear elements 5 by a suitable adhesive.

[0032] Subsequently, the linear elements 5, together with the film 9, are firmly secured on the frame 3 as shown in Figure 7C. Then, predetermined linear elements 5 are removed to form the openings 7 as shown in Figure 7D. When the unnecessary linear elements 5 are removed, the associated film is also removed. As a result, the mask 1C is prepared.

[0033] It should be noted that the linear element 5 is circle in the cross sectional shape in the foregoing description, but the present invention is not limited in this regard. For instance, the linear element 5 may be polygonal in the cross sectional shape.

[0034] All the linear elements 5 may not be made from a single material. For example, if the linear elements 5 are categorized into "unnecessary" or "to be removed" elements and "necessary" or "to remain" elements, the "to be removed" elements may be made from an acid-corrosive material and the "to remain" elements may be made from an acid-resistive material. The "to be removed" elements are those linear elements which are removed in the process of Figure 5C to form the openings 7. The frame 3 may also be made from the acid-resistive material. In this case, the process of Figure 5C to remove the unnecessary linear elements can be performed by immersing all the linear elements together with the frame 3 (Figure 5B) in an acid pool (not shown).

[0035] If the linear elements 5 and frame 3 deform upon heating, the linear elements 5 may be fused and fixed to the frame 3 by heating. In this case, no fixing agent such as an adhesive is needed to connect the linear elements 5 onto the frame 3.

[0036] The shape and location of the window 2 and the shape of the frame 3 are not limited to those illustrated and described. For instance, the window 2 may have any suitable polygonal shape.

Claims

1. A mask assembly (1) having a predetermined opening pattern (7) used to form a thin layer having the same pattern on a substrate, comprising:

a frame (3) having a window (2), the window having an edge; and

a masking part (4) supported by the edge of the window (2), the masking part (4) including a plurality of shielding portions (6) spaced from each other to form the predetermined opening pattern (7),

characterized in that each of the plurality of shielding portions (6) includes a plurality of parallel linear elements (5) arranged next to each other.

2. The mask assembly according to claim 1, wherein each of the plurality of shielding portions (6), has a multi-layer structure made by the plurality of linear elements (5) arranged in a plurality of layers.

3. The mask assembly device according to claim 1 or 2, wherein the predetermined opening pattern is made by removing predetermined one or more linear elements (5).

4. The mask assembly according to any one of claims 1 to 3, wherein each of the plurality of shielding portions (6) has a coating member (8) to cover the at least one linear element (5).

5. The mask assembly according to any one of claims 1 to 3, wherein each of the plurality of shielding portions (6) has a film member (9) to cover the at least one linear element (5).

6. The mask assembly according to any one of claims 1 to 5, wherein each of the at least one linear element (5) is made from an acid-resistive material.

7. The mask assembly according to any one of claims 1 to 6, wherein each of the at least one linear element (5) is a resin wire.

8. The mask assembly according to any one of claims 2 to 7, wherein the multi-layer structure includes an upper layer and a lower layer, and the linear elements (5) of the lower layer are arranged to seal gaps between the linear elements of the upper layer.

9. A method of making a mask assembly (1), the mask assembly having a predetermined opening pattern (7) used to form a thin layer of the same pattern on a substrate, comprising:

providing a masking part (6) that includes a plurality of linear elements (5) arranged next to each other; and

removing at least one predetermined linear element from the plurality of linear elements to form the predetermined opening pattern.

10. The method according to claim 9, wherein the step of providing a masking part (6) and the step of removing the at least one predetermined linear element (5) are repeated at least twice.

11. The method according to claim 9 or 10 further including providing a coating (8) over the plurality of linear elements (5).

12. The method according to claim 9, or 10 further including providing a film (9) over the plurality of linear elements (5).

13. The method according to any one of claims 9 to 12, wherein the plurality of linear elements (5) are made from an acid-resistive material except for the at least one predetermined linear element.

14. The method according to any one of claims 9 to 13, wherein each of the plurality of linear elements (5) is a resin wire.

15. The method according to any one of claims 9 to 14, wherein the at least one predetermined linear element (5) is made from an acid-corrosive material, and the step of removing the at least one predetermined linear element includes immersing the plurality of linear elements into an acid pool.

16. The method according to any one of claims 9 to 15 further including attaching the plurality of linear elements (5) on a frame (3).

17. The method according to claim 16, wherein the step of attaching the plurality of linear elements (5) is performed while a tension is being applied to the plurality of linear elements.

Revendications

1. Assemblage formant masque (1) présentant un motif d'ouverture prédéterminé (7) utilisé pour former une couche mince ayant le même motif sur un substrat, l'assemblage comprenant :

un cadre (3) comportant une fenêtre (2), la fenêtre ayant un bord ; et

une partie de masquage (4) supportée par le bord de la fenêtre (2), la partie de masquage (4) comprenant une pluralité de portions d'écran (6) espacées les unes par rapport aux autres pour réaliser le motif d'ouverture prédéterminé (7), caractérisé en ce que chacune de la pluralité de portions d'écran (6) comprend une pluralité d'éléments linéaires parallèles (5) disposés les uns à côté des autres.

2. Assemblage formant masque selon la revendication 1, dans lequel chacune de la pluralité de portions d'écran (6) possède une structure multicouche constituée par la pluralité d'éléments linéaires (5) agencés en une pluralité de couches.

3. Assemblage formant masque selon la revendication 1 ou 2, dans lequel le motif d'ouverture prédéterminé est réalisé en retirant un ou plusieurs éléments linéaires (5) prédéterminés.

4. Assemblage formant masque selon l'une quelconque des revendications 1 à 3, dans lequel chacune de la pluralité de portions d'écran (6) est pourvue d'un élément de revêtement (8) destiné à recouvrir le au moins un élément linéaire (5).

5. Assemblage formant masque selon l'une quelconque des revendications 1 à 3, dans lequel chacune de la pluralité de portions d'écran (6) est pourvue d'un élément de film (9) destiné à recouvrir le au moins un élément linéaire (5).

6. Assemblage formant masque selon l'une quelconque des revendications 1 à 5, dans lequel chacun des au moins un élément linéaire (5) est fait en un matériau résistant aux acides.

7. Assemblage formant masque selon l'une quelconque des revendications 1 à 6, dans lequel chacun des au moins un élément linéaire (5) est un fil en résine.

8. Assemblage formant masque selon l'une quelconque des revendications 2 à 7, dans lequel la structure multicouche comprend une couche supérieure et une couche inférieure, et les éléments linéaires (5) de la couche inférieure sont disposés de façon à fermer hermétiquement des espaces entre les éléments linéaires de la couche supérieure.

9. Procédé de fabrication d'un assemblage formant masque (1), l'assemblage formant masque présentant un motif d'ouverture prédéterminé (7) utilisé pour former une mince couche ayant le même motif sur un substrat, le procédé comprenant les étapes consistant à :

fournir une partie de masquage (6) qui comprend une pluralité d'éléments linéaires (5) disposés les uns à côté des autres ; et

retirer au moins un élément linéaire prédéterminé de la pluralité d'éléments linéaires pour former le motif d'ouverture prédéterminé.

10. Procédé selon la revendication 9, dans lequel l'étape consistant à fournir une partie de masquage (6) et l'étape consistant à retirer le au moins un élément linéaire prédéterminé (5), sont répétées au moins deux fois.

11. Procédé selon la revendication 9 ou 10, comprenant en outre l'étape consistant à fournir un revêtement (8) par dessus la pluralité d'éléments linéaires (5).

12. Procédé selon la revendication 9 ou 10, comprenant en outre l'étape consistant à fournir un film (9) par dessus la pluralité d'éléments linéaires (5).

13. Procédé selon l'une quelconque des revendications 9 à 12, dans lequel la pluralité d'éléments linéaires (5) est faite en un matériau résistant aux acides, sauf en ce qui concerne le au moins un élément linéaire prédéterminé.

14. Procédé selon l'une quelconque des revendications 9 à 13, dans lequel chacun de la pluralité d'éléments linéaires (5) est un fil en résine.

15. Procédé selon l'une quelconque des revendications 9 à 14, dans lequel le au moins un élément linéaire prédéterminé (5) est fait en un matériau corrosif pour des acides, et l'étape consistant à retirer le au moins un élément linéaire prédéterminé comprend l'étape consistant à immerger la pluralité d'éléments linéaires dans un bain d'acide.

16. Procédé selon l'une quelconque des revendications 9 à 15, comprenant en outre l'étape consistant à fixer la pluralité d'éléments linéaires (5) sur un cadre (3).

17. Procédé selon la revendication 16, dans lequel l'étape de fixation de la pluralité d'éléments linéaires (5) est exécutée pendant qu'une tension est appliquée sur la pluralité d'éléments linéaires.

Ansprüche

1. Maskenbaugruppe (1) mit einem vorbestimmten Öffnungsmuster (7), welche zum Ausbilden einer dünnen Schicht mit demselben Muster auf einem Substrat verwendet wird, umfassend:

einen Rahmen (3) mit einem Fenster (2), wobei das Fenster eine Kante aufweist; und

einen maskierenden Teil (4), welcher durch die Kante des Fensters (2) getragen wird, wobei der maskierende Teil (4) eine Mehrzahl von Abschirmabschnitten (6) enthält, welche voneinander beabstandet sind, um das vorbestimmte Öffnungsmuster (7) auszubilden,

dadurch gekennzeichnet, dass jeder aus der Mehrzahl von Abschnitten (6) eine Mehrzahl von parallelen, linearen Elementen (5) enthält, welche aneinander angeordnet sind.

2. Maskenbaugruppe gemäß Anspruch 1, wobei jeder aus der Mehrzahl von Abschirmabschnitten (6) einen Mehrschichtaufbau aufweist, welcher durch die Mehrzahl von linearen Elementen (5) gebildet wird, welche in einer Mehrzahl von Schichten angeordnet sind.

3. Maskenbaugruppeneinrichtung gemäß Anspruch 1 oder 2, wobei das vorbestimmte Öffnungsmuster durch Entfernen von einem oder mehreren vorbestimmten Elementen (5) hergestellt wird.

4. Maskenbaugruppe gemäß irgendeinem der Ansprüche 1 bis 3, wobei jeder aus der Mehrzahl von Abschirmabschnitten (6) ein Beschichtungselement (8) aufweist, um das zumindest eine lineare Element (5) zu bedecken.

5. Maskenbaugruppe gemäß irgendeinem der Ansprüche 1 bis 3, wobei jeder aus der Mehrzahl von Abschirmabschnitten (6) ein Filmelement (9) aufweist, um das zumindest eine lineare Element (5) zu bedecken.

6. Maskenbaugruppe gemäß irgendeinem der Ansprüche 1 bis 5, wobei jedes von dem zumindest einem linearen Element (5) aus säurebeständigem Material hergestellt ist.

7. Maskenbaugruppe gemäß irgendeinem der Ansprüche 1 bis 6, wobei jedes von dem zumindest einem linearen Element (5) ein Harzdraht ist.

8. Maskenbaugruppe gemäß irgendeinem der Ansprüche 2 bis 7, wobei der Mehrschichtaufbau eine obere Schicht und eine untere Schicht enthält, und die linearen Elemente (5) der unteren Schicht zu Dichtungsspalten zwischen den linearen Elementen der oberen Schicht angeordnet sind.

9. Verfahren zur Herstellung einer Maskenbaugruppe (1), wobei die Maskenbaugruppe ein vorbestimmtes Öffnungsmuster (7) aufweist, welches zum Ausbilden einer dünnen Schicht desselben Musters auf einem Substrat verwendet wird, umfassend:

Bereitstellen eines maskierenden Teils (6), welcher eine Mehrzahl von linearen Elementen (5) enthält, welche nebeneinander angeordnet sind, und

Entfernen von zumindest einem linearen Element aus der Mehrzahl von linearen Elementen, um das vorbestimmte Öffnungsmuster auszubilden.

10. Verfahren gemäß Anspruch 9, wobei der Schritt des Bereitstellens eines maskierenden Teils (6) und der Schritt des Entfernens des zumindest einen vorbestimmten linearen Elements (5) zumindest zweimal wiederholt werden.

11. Verfahren gemäß Anspruch 9 oder 10, ferner umfassend das Vorsehen einer Beschichtung (8) über der Mehrzahl von linearen Elementen (5).

12. Verfahren gemäß Anspruch 9 oder 10, ferner enthaltend das Vorsehen eines Films (9) über der Mehrzahl von linearen Elementen (5).

13. Verfahren gemäß irgendeinem der Ansprüche 9 bis 12, wobei die Mehrzahl von linearen Elementen (5) aus einem säurebeständigen Material mit Ausnahme des zumindest einen vorbestimmten linearen Elements hergestellt sind.

14. Verfahren gemäß irgendeinem der Ansprüche 9 bis 13, wobei jedes der Mehrzahl von linearen Elementen (5) ein Harzdraht ist.

15. Verfahren gemäß irgendeinem der Ansprüche 9 bis 14, wobei das zumindest eine vorbestimmte lineare Element (5) aus einem säurekorrosiven Material hergestellt ist, und der Schritt des Entfernens des zumindest einen vorbestimmten linearen Elements das Versenken der Mehrzahl von linearen Elementen in ein Säurebecken enthält.

16. Verfahren gemäß irgendeinem der Ansprüche 9 bis 15, ferner enthaltend das Anfügen der Mehrzahl von linearen Elementen (5) auf einen Rahmen (3).

17. Verfahren gemäß Anspruch 16, wobei der Schritt des Anfügens der Mehrzahl von linearen Elementen (5) durchgeführt wird, während eine Spannung auf die Mehrzahl von linearen Elementen ausgeübt wird.

Drawing